Kessler R.C.,Harvard University | Birnbaum H.,Analysis Group | Bromet E.,State University of New York at Stony Brook | Hwang I.,Harvard University | And 2 more authors.Psychological Medicine | Year: 2010

The moon's far hemisphere is never directly visible from Earth and while it has been photographed, with the first images appearing in 1959, it has never been explored.
China's Chang'e-4 probe—named for the goddess of the moon in Chinese mythology—will be sent to it in 2018, the official Xinhua news agency reported.
"The Chang'e-4's lander and rover will make a soft landing on the back side of the moon, and will carry out in-place and patrolling surveys," it cited the country's lunar exploration chief Liu Jizhong as saying on Thursday.
Beijing sees its military-run, multi-billion-dollar space programme as a marker of its rising global stature and mounting technical expertise, as well as evidence of the ruling Communist Party's success in transforming the once poverty-stricken nation.
But for the most part it has so far replicated activities that the US and Soviet Union pioneered decades ago.
"The implementation of the Chang'e-4 mission has helped our country make the leap from following to leading in the field of lunar exploration," Liu added.
In 2013, China landed a rover dubbed Yutu on the moon and the following year an unmanned probe completed its first return mission to the earth's only natural satellite.
Beijing has plans for a permanent orbiting station by 2020 and eventually to send a human to the moon.
Space flight is "an important manifestation of overall national strength", Xinhua cited science official Qian Yan as saying, adding that every success had "greatly stimulated the public's... pride in the achievements of the motherland's development."
Clive Neal, chair of the Lunar Exploration Analysis Group affiliated with NASA, confirmed that the Chang'e-4 mission was unprecedented.
"There has been no surface exploration of the far side," he told AFP Friday.
It is "very different to the near side because of the biggest hole in the solar system—the South Pole-Aitken basin, which may have exposed mantle materials—and the thicker lunar crust".
The basin is the largest known impact crater in the solar system, nearly 2,500 kilometres wide and 13 kilometres deep.
"I am sure the international lunar science community will be very excited about this mission," he told AFP. "I know I am."